AT42QT2161-MMU Atmel, AT42QT2161-MMU Datasheet - Page 22

• Manufacturer Part Number: AT42QT2161-MMU
• Description: IC TOUCH SENSOR 16KEY QFN M-MOD
• Manufacturer: Atmel
• Type: Capacitiver

Specifications of AT42QT2161-MMU

• Touch Panel Interface: 8, 2-Wire
• Number Of Inputs/keys: 16 Key, Slider
• Resolution (bits): 10 b
• Data Interface: I²C, Serial
• Voltage Reference: Internal
• Voltage - Supply: 1.8 V ~ 5.5 V
• Current - Supply: 1.14mA
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 28-VFQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

5. Interfaces
5.1
5.2
5.3
5.3.1
22
I
I
Data Read/Write
2
2
AT42QT2161
C-compatible Protocol
C-compatible Addresses
Writing Data to the Device
The
reads and writes.
Note: Each write or read cycle must end with a stop condition. The QT2161 may not respond
correctly if a cycle is terminated by a new start condition.
Four preset
Table 5-1.
The sequence of events required to write data to the device is shown next.
The host initiates the transfer by sending the START condition, and follows this by sending the
slave address of the device together with the Write-bit. The device sends an ACK. The host then
sends the memory address within the device it wishes to write to. The device sends an ACK.
The host transmits one or more data bytes; each will be acknowledged by the device.
Key
S
SLA+W
A
MemAddress
Data
P
I
2
C
-compatible protocol is based around access to an address table and supports multibyte
I
2
I2CA1
C
I
-compatible addresses are selectable through pin I2CA0 and I2CA1
2
0
0
1
1
C
S
-compatible Addresses
SLA+W
A
Host to Device
MemAddress
Start condition
Slave address plus write bit
Acknowledge bit
Target memory address within device
Data to be written
Stop condition
I2CA0
0
1
0
1
A
Data
Device to Host
A
Address
P
0x0D
0x6B
0x17
0x44
9614A–AT42–08/10
(Table
5-1).